Low trauma hip fractures, due to bone fragility, are a major healthcare burden with serious consequences for individuals in terms of long-term morbidity and mortality; and also for society due to the high medical and care costs associated with these injuries. Because of the association with low bone mass, these fractures are particularly prevalent in elderly populations and are likely to become more common as longevity increases globally. Avoidance of these fractures is therefore an extremely important goal. Low bone mass, manifested in the conditions of osteopenia and osteoporosis, is the primary cause of bone fragility, and reductions in bone mass are the inevitable corollary of aging and menopause. Bone loss may be exacerbated by immobilisation and reduced weight-bearing activity, giving rise to the condition of disuse osteopenia. Immobilisation may itself be the result of low trauma leg fragility fractures that potentially causes further bone density loss. If this loss occurs at the hip, there is an increased risk for hip fracture as a sequela to the original injury. Osteoarthritis is also a condition strongly associated with aging that may necessitate knee arthroplasty as a last stage treatment, potentially causing a period of reduced mobility and weight-bearing activity following surgery. Leg fracture and knee replacement both present additional risk factors for hip fracture due to changes in muscle mass, gait and postural stability that may increase the risk of falls. This study aims primarily to investigate the effects of immobilisation on leg fracture and knee replacement patients, immediately following injury or surgery, in order to quantify bone and muscle loss and to monitor recovery over a one year period. A postmenopausal population were studied as they are already losing bone density systemically and may be at greater risk of further bone loss following immobilisation. Factors of activity, function, weight-bearing, pain, treatments, therapies, health perceptions and mental wellbeing, that potentially contribute to bone loss and recovery, were also investigated. Results from the study may provide information relating to increased future hip fracture risk and lead to treatment options to alleviate bone loss in these groups.

Discharge readiness following total knee replacement (TKR) has often been defined using quantitative factors, such as knee range of motion or walking a specified distance. These measurements fail to include other features that could impact readiness for discharge, such as social support or patient perceptions. Most patients have positive results following TKR surgery, however others experience negative outcomes such as falls, reduced functional performance, and hospital readmission. Readiness for returning home after TKR begins with pre-operative education to prepare patients for surgery and the post-operative phase. Health care providers must have a clear understanding of patients’ perceptions of readiness to return home after surgery. It is also essential to describe the current structure of pre-operative education nationally as a mechanism for better preparing patients to return home following knee replacement. This dissertation includes three studies that explore aspects of discharge readiness following TKR including patients’ perceptions of readiness for discharge as well as the structure of pre-operative education for TKR across the United States. The first study examined patients’ experiences preparing for discharge home from the acute care setting following TKR surgery. Results indicated that patients felt prepared overall for discharge and received appropriate supports for returning home after surgery, but some felt unprepared for certain aspects of recovery such as the amount of pain experienced in the post-operative phase. The second study surveyed health care providers who participated in pre-operative education before TKR to identify the current structure of education programs in the United States. This pilot study revealed that pre-operative education teams were commonly interprofessional with education being typically provided in a group format in a single session lasting between 1 and 1.5 hours. Verbal and written instruction were common delivery methods to provide education. The final dissertation study used mixed-methods to explore the current structure of pre-operative education for TKR in the United States with a large, national sample. Orthopedic nurses completed an online survey to describe their pre-operative education program. The majority of participants provided pre-operative education as part of interprofessional teams in either a group format or a format that included both group and individual education. Verbal instruction was the most common educational delivery method followed by written instruction. Most pre-operative education classes lasted between 1 and 1.5 hours, were delivered in a single session, and included a variety of topics. Ten orthopedic nurses were then interviewed and interview transcripts were analyzed qualitatively for common themes among participants. Participants expressed that pre-operative education was a significant component impacting patient outcomes following surgery. Interprofessional pre-operative education was valued by participants, but pragmatic factors were identified as barriers to the inclusion of other disciplines within these programs. Education programs were constantly evolving based on current evidence-based practice and changes to orthopedic protocols. Descriptions of pre-operative programs nationally combined with providers’ perceptions provides a strong basis for determining best practice to support better post-operative patient outcomes. This dissertation research culminated in recommendations for best practice as well as the creation of a model, the ICF-I-EDUCATE, which combines the International Classification of Health, Functioning and Disability (ICF), interprofessional practice, and the EDUCATE model for providing patient and family education. Research is needed to examine the ICF-I-EDUCATE model in clinical practice for patients with planned TKR.

Little is known about time to return to work (TRTW) following planned medical events. This study was a secondary analysis (n=94) to determine predictors of time to return to work following a total knee replacement for osteoarthritis. Significant predictors of delayed TRTW following a knee replacement: 1) use of workplace modifications (in 6wks vs 5 wks) and 2) poor physical function (in 7wks vs 6 wks). These findings have large implications for workers undergoing knee replacement, orthopedic clinicians, and occupational health nurses.

Tyrimo tikslas – įvertinti kineziterapijos pratimų ir keturgalvio šlaunies raumens elektrinės stimuliacijos poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judėjimo funkcijai. Uždaviniai: 1. Nustatyti kineziterapijos pratimų poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judesių amplitudei, raumenų jėgai, skausmo intensyvumui, kelio tinimui ir funkcinei būklei. 2. Nustatyti kineziterapijos pratimų, derinamų su raumenų elektrine stimuliacija, poveikį moterų, kurioms endoprotezuotas kelio sąnarys, judesių amplitudei, raumenų jėgai, skausmo intensyvumui, kelio tinimui ir funkcinei būklei. 3. Palyginti skirtingų kineziterapijos programų efektyvumą. Išvados: 1. Taikant kineziterapijos pratimus statistiškai reikšmingai padidėjo moterų, kurioms endoprotezuotas kelio sąnarys, operuotos kojos kelio judesių amplitudės, raumenų jėga, sumažėjo skausmo intensyvumas, kelio tinimas bei pagerėjo funkcinė būklė. 2. Taikant kineziterapijos pratimus ir keturgalvio šlaunies raumens elektrinę stimuliaciją statistiškai reikšmingai padidėjo moterų, kurioms endoprotezuotas kelio sąnarys, operuotos kojos kelio judesių amplitudės, raumenų jėga, sumažėjo skausmo intensyvumas, kelio tinimas bei pagerėjo funkcinė būklė. 3. Kineziterapijos pratimai, derinami su keturgalvio šlaunies raumens elektrine stimuliacija, labiau padidino blauzdą tiesiančių raumenų jėgą ir pagerino „Stotis ir eiti“ testo rezultatus nei vien kineziterapijos pratimai. Judesių amplitudei, skausmo intensyvumui, kelio... [toliau žr. visą tekstą] / The aim of the study: to evaluate the effect of physical therapy exercises and electrical stimulation of the quadriceps muscle on motor function in women after total knee replacement. Goals of the study: 1. To assess the effect of physical therapy exercises for range of motion, muscles strength, pain intensity, knee swelling and functional performance in women after total knee replacement. 2. To determine the effect of physical therapy exercises combined with neuromuscular electrical stimulation for range of motion, muscle strength, pain intensity, knee swelling and functional performance in women after total knee replacement. 3. To compare the effectiveness of different physical therapy programs. Coclusions: 1. Physical therapy exercises have significantly increased the knee range of motion, muscle strength, decreased pain intensity, the swelling of the knee and improved functional performance for women after total knee replacement surgery. 2. Physical therapy exercises with quadriceps muscle neuromuscular electrical stimulation have significantly increased the knee range of motion, muscle strength, decreased pain intensity, the swelling of the knee and improved functional performance for women after total knee replacement surgery. 3. Physical therapy exercises combined with quadriceps muscle neuromuscular electrical stimulation whilst compared to physical therapy exercises alone increased the strength of quadriceps muscle and results of “Timed up and go” test more. Both... [to full text]

This longitudinal, descriptive study based on Bandura's self-efficacy theory (1977), examined the effects of educational activities on self-efficacy and of self-efficacy on functional ability in everyday activities in clients undergoing elective, primary, unilateral, total knee arthroplasty (TKA). Educational activities included: attending a joint replacement class and a physical therapy session, performing exercises, and reading educational materials. Other sources of client information were also discussed. Self efficacy was assessed regarding confidence in ability to perform activities required for discharge home. Cronbach's alpha for the self-efficacy scale was .94 (pre-education) and .81 (post-education). Functional ability in everyday activities was operationalized as length of hospital stay, discharge placement, and perceived health status. Perceived health status was assessed using the three-scale Western Ontario McMasters University Osteoarthritis Index (WOMAC). Cronbach's alpha was: pain .85, joint stiffness .76, and physical function .94 (preoperatively); and pain .86, joint stiffness .80, and physical function .94 (postoperatively).Evidence was collected from a convenience sample of 31 participants: (a) when the process of scheduling surgery began; (b) before surgery, after the client had opportunities to participate in educational activities, and (c) approximately six weeks after surgery. The orthopedic surgeon and professional staff reviewed instruments for validity. Five clients reviewed the questionnaires for understandability and readability. Data were analyzed using Pearson r correlation coefficients, independent samples t-tests, analyses of variance and chi-square tests. An alpha level of .05 was designated as significant.Higher self-efficacy scores were associated with more expected benefits, previous TKA, and greater pain relief. Lower self-efficacy scores correlated with greater improvement in self-efficacy. Shorter lengths of hospital stay were associated with greater joint stiffness reduction, younger age and previous TKA. Discharge home was associated with younger age and living with someone else. Participants that were "very sure" of the need for TKA exhibited higher self-efficacy scores than participants that were "unsure". Improved outcomes were not associated with any one type of educational activity.This study highlighted the need for further refinement of context sensitive self-efficacy instruments, more sophisticated means of assessing the impact of an increasing array of information sources and more longitudinal studies with larger sample sizes. / Department of Educational Leadership

This master´s thesis deals with the experimental analysis of the coefficient of friction and lubrication film in total knee replacement. The experiments are performed on a knee joint simulator, with an implemented module for measuring friction. To observe film formation, fluorescent microscopy is used. The experiments are mainly focused on a detailed description of the influence of parameters occurring during the gait cycle. This approach should significantly help in describing the tribological processes that occur in the total knee replacement. The results confirm previous investigations in terms of axial load, where the coefficient of friction decreases with the increasing load. In the case of lubrication film, no significant changes are observed. On the contrary, while investigating the influence of SRR, noticeable changes in film formation are observed while the coefficient of friction being unaffected. While describing the whole gait cycle, precise results are obtained only in the first half of the cycle as the second half is accompanied by the occurrence of large deviations from a rapid decrease of load. This work provides a better understanding of the field of lubrication film in total knee replacements. Moreover, thanks to the simultaneous measurement of the coefficient of friction and the observation of the contact area, it is possible to draw better conclusions than if the experiments had been carried out separately.

In this work we discuss the design and implementation of a computer program to simulate the wear on knee implants over a standardized gait cycle. The contact problems during the gait cycle are formulated using linear elasticity with a linear non-penetration condition. Archard's wear law is used to estimate long-term wear. The algebraic problem after discretization is solved using the Truncated Nonsmooth Newton Multigrid (TNNMG) algorithm. The linear correction step of the algorithm leads to indefinite systems in our application for which we describe a novel heuristic damping algorithm. Our problem sizes allow using a direct solver for these systems and with some modifications we are able to reuse the Cholesky factorization of the system matrix over multiple iterations of the TNNMG algorithm. For our application we are able to significantly improve over the performance of IPopt, a state-of-the-art solver using penalty-based methods. The program is then used for in-silico simulations of wear of two different total knee implant models for which in-vitro results are also available. Both wear volume and spatial distribution of wear that are computed compare well with the experimental results.

Osteoarthritis (OA) of the knee, a musculoskeletal disease characterized by degenerations in multiple joint tissues including the articular cartilage and subchondral bone, is a major clinical challenge worldwide that currently has no cure. Traumatic knee injuries such as anterior cruciate ligament (ACL) tear predispose subjects to early onset of post-traumatic OA (PTOA), necessitating the development of effective disease modifying therapies as total knee replacement surgeries have a limited lifetime. Significant knowledge gap remains in the pathogenesis of OA, while recent evidence suggests the important role of subchondral bone microstructure and mechanics in OA development. Subchondral bone is composed of the subchondral bone plate, a thin layer of cortical lamella, and the subchondral trabecular bone, composed of individual plate-like and rod-like trabeculae. These trabecular plates and rods determine the microstructure and mechanics of trabecular bone entirely and can be quantitatively analyzed using individual trabecula segmentation (ITS). Recent application of ITS showed that changes in the plate-and-rod microstructure of subchondral trabecular bone precede cartilage damage and are implicated to play a role in disease pathogenesis. Studies presented in this thesis aim to provide a deeper understanding of subchondral bone in knee OA scientifically and clinically, which may ultimately be used to improve diagnosis, prevention and treatment of this prevalent and disabling disease. In the first study, we comprehensively quantified microstructural and tissue biomechanical properties of the subchondral bone and articular cartilage in human knee specimens with advanced OA and control knees without OA. We found reduced tissue modulus in trabecular plates and rods in regions with moderate OA, where cartilage is still intact, that persisted in severe OA regions, where cartilage is severely damaged. These observations suggest that tissue biomechanical changes in the subchondral trabecular bone may precede cartilage damage in OA development. Furthermore, we found strong correlations between structural and mechanical parameters of the cartilage and subchondral bone in CT knees, suggesting cross-talk at the tissue level. This coupling persisted in moderate OA regions but disappeared in severe OA regions, suggesting that loss of tissue crosstalk may be an additional indicator of disease progression. In the second study, we quantified subchondral bone microstructural changes after ACL tear in vivo in human subjects using the second-generation high resolution peripheral quantitative computed tomography (HR-pQCT). We examined short-term longitudinal changes during the acute phase (~18 days to ~141 days) after injury, as well as long-term adaptations (~5 years post injury) in the injured knee relative to the contralateral knee in a cross-sectional cohort. We found subchondral bone loss within 1 month from injury that primarily targeted trabecular rods, especially at the distal femur. We also found increased spatial heterogeneity in subchondral trabecular microstructure within the injured knees compared to the contralateral knees in the long-term after injury. These findings indicate that ACL tear results in both short-term and long-term microstructural adaptations in the subchondral bone. ITS based on HR-pQCT knee scans may be a valuable tool to monitor disease progression in vivo. Finally, we quantified subchondral bone microstructural changes after ACL-transection in a canine model of PTOA and investigated the effects of bisphosphonate and NSAID treatment on subchondral bone changes and OA progression. Studies were conducted in skeletally-mature and juvenile animals to investigate the effect of injury age. We found that subchondral bone adaptations after surgery and treatment effects depended on skeletal maturity of animals. In mature animals, changes in the microstructure of trabecular plates and rods occurred 1-month post-op and persisted until 8-months post-op. Bisphosphonate treatment attenuated these microstructural changes and cartilage degeneration while NSAID treatment did not. In juvenile animals that have not reached skeletal maturity, transient changes in trabecular plate and rod microstructure occurred at 3-months post-op but disappeared by 9-months post-op. Neither bisphosphonate nor NSAID treatment attenuated bone microstructural changes or cartilage damages. These findings suggest that age and skeletal maturity at time of injury may need to be considered as additional factors in studying PTOA progression and developing preventative treatments. Taken together, these studies highlight the importance of microstructural and tissue biomechanical changes of subchondral bone in the development of OA. In vivo quantification of subchondral bone using advanced imaging modalities enable longitudinal monitoring of disease progression. Therapeutic agents targeting subchondral bone changes after traumatic injury may be effective preventative strategies for PTOA.

Modern advances in technology have allowed for an increase in the precision with which we are able to measure, record, and affect behavior. These developments suggest that the domains in which behavior analysis might contribute are considerably broader than previously appreciated, for instance the area of behavioral medicine. One way the field of behavior analysis can begin to address problems in behavioral medicine is with biosensor technology, like surface electromyography (sEMG). For sEMG technology to be useful in behavioral medicine, specifically recovery from total knee arthroplasty, a reference value (the maximum voluntary individual contraction-MVIC) must be established. The MVIC value allows for the comparison of data across days and may allow the programming of contingencies. However, current MVIC methods fall short. Study 1 compares MVIC values produced by a participant given the typical instruction only method with two alternative methods: instruction + feedback, and instruction + feedback in a game context. Across 10 participants both feedback conditions lead to higher MVIC values then the instruction only condition. Study 2 applies the MVIC techniques developed during Study 1 to an exercise procedure. Using an MVIC value as the criteria for feedback Study 2 compares the same three conditions, however this time assessing for the conditions under which exercise performance is optimal. Across all 9 participants the instruction + feedback in a game context lead to the participant ‘working harder' and 8 out of 9 participants exceeded the MVIC value more often during this condition then in the other two conditions.

Knee osteoarthritis affects approximately 25 million adults. In severe cases, total knee arthroplasty (TKA) is the most common solution. TKA is effective at addressing pain and reducing continued degeneration of articular cartilage. However, effective physical therapy (PT) following TKA is vital for a full functional recovery. Despite the importance of PT, half of patients never achieve a full functional recovery. Decreases in proprioceptive feedback, severe atrophy, and pain inhibition all likely contribute to the variability in effectiveness. Surface electromyography-based biofeedback (sEMGBF) may allow clinicians to address some of these barriers by supplementing proprioceptive feedback and targeting small muscle contractions before eventually increasing the contraction requirement. Using a between group design, we compare the effectiveness of sEMGBF (7) to neuromuscular stimulation (NMES) (6), and a control group (6) in recovery following TKA. Effectiveness was evaluated across 4 metrics (quadriceps strength, range of motion, functional improvement, and quality of life) in a pre-test/post-test fashion. At the statistical level this study suggest that sEMGBF leads to greater improvements in quadriceps strength relative to the NMES and control group. Additionally, visual analysis suggests that sEMGBF may also lead to greater improvements in range of motion, and functional improvement relative to the NMES and control group. The results for quality of life are mixed. Overall, the study provides initial clinical support for the utility of sEMGBF following TKA.